WASHINGTON — The Internal Revenue Service today issued guidance reflecting statutory changes regarding the use of certain tax-favored arrangements, such as flexible spending arrangements (FSAs), to pay for over-the-counter medicines and drugs.

The Affordable Care Act, enacted in March, established a new uniform standard that, effective Jan. 1, 2011, applies to FSAs and health reimbursement arrangements (HRAs). Under the new standard, the cost of an over-the-counter medicine or drug cannot be reimbursed from the account unless a prescription is obtained. The change does not affect insulin, even if purchased without a prescription, or other health care expenses such as medical devices, eye glasses, contact lenses, co-pays and deductibles. The new standard applies only to purchases made on or after Jan. 1, 2011, so claims for medicines or drugs purchased without a prescription in 2010 can still be reimbursed in 2011, if allowed by the employer’s plan.